CONVERSIONS

 

Scroll down or click on any of these:

Ring sizes and finger sizes, international conversions 

Converting clock and watch winder sizes to mm

Weights conversions

Links to conversions for other weights and measures


Ring / finger sizes

Click here to buy ring sticks and finger sizers

U.S.  Size

Diameter
in Inches

Diameter
in MM

Metric MM
Equivalent

British 

French 

German 

Japanese 

Swiss 

0000

.390

9.91

 

-

 

 

 

 

00

.422

10.72

 

-

 

 

 

 

0

.454

11.53

 

-

 

 

 

 

1/2

.474

11.95

 

A

 

 

 

 

3/4

.482

12.18

 

A 1/2

 

 

 

 

1

.487

12.37

38.9

B

 

 

1

 

1 1/4

-

12.60

39.6

B 1/2

 

 

 

 

1 1/2

.503

12.78

40.2

C

 

 

 

 

1 3/4

-

13.00

40.8

C 1/2

 

 

 

 

2

.520

13.21

41.5

D

41 1/2

13 1/2

2

1 1/2

2 1/4

-

13.41

42.1

D 1/2

-

-

 

 

2 1/2

.536

13.61

42.7

E

42 3/4

13 3/4

3

2 3/4

2 3/4

-

13.83

43.4

E 1/2

-

-

 

 

3

.553

14.05

44.0

F

44

14

4

4

3 1/8

-

14.15

44.3

F 1/2

-

-

 

 

3 1/4

-

14.25

44.6

-

-

-

 

 

3 3/8

-

14.36

44.9

G

45 1/4

-

5

5 1/4

3 1/2

.569

14.45

45.2

-

-

14 1/2

 

 

3 5/8

-

14.56

45.6

 G 1/2

-

 

6

 

3 3/4

-

14.65

45.9

H

46 1/2

 

 

6 1/2

4

.585

14.86

46.5

H 1/2

-

15

7

 

4 1/4

-

15.04

47.1

I 

47 3/4

 

 

7 3/4

4 1/2

.601

15.27

47.8

I 1/2

-

15 1/4

8

 

4 5/8

-

15.40

48.1

J

49

15 1/2

 

9

4 3/4

-

15.53

48.4

-

-

 

 

 

5

.618

15.70

49.0

J 1/2

-

15 3/4

9

 

5 1/8

-

15.80

49.3

K

50

 

 

10

5 1/4

-

15.90

49.6

-

-

 

 

 

5 3/8

-

16.0

50.0

K 1/2

-

 

10

 

5 1/2

.634

16.10

50.3

L

51 3/4

16

 

11 3/4

5 3/4

-

16.30

50.9

-

-

 

 

 

5 7/8

-

16.41

51.3

L 1/2

-

 

 

 

6

.650

16.51

51.5

M

52 3/4

16 1/2

12

12 3/4

6 1/4

-

16.71

52.2

M 1/2

-

 

 

 

6 1/2

.666

16.92

52.8

N

54

17

13

14

7

.683

17.35

54.0

O

55 1/4

17 1/4

14

15 1/4

7 1/4

-

17.45

54.7

O 1/2

-

 

 

 

7 1/2

.699

17.75

55.3

P

56 1/2

17 3/4

15

16 1/2

7 3/4

-

17.97

55.9

P 1/2

-

 

 

 

8

.716

18.19

56.6

Q

57 3/4

18

16

17 3/4

8 1/4

-

18.35

57.2

Q 1/2

-

 

 

 

8 1/2

.732

18.53

57.8

-

-

18 1/2

17

 

8 5/8

-

18.61

58.4

R

59

 

 

19

8 3/4

-

18.69

58.4

-

-

 

 

 

8 7/8

-

18.80

59.0

R 1/2

-

 

 

 

9

.748

18.89

59.1

-

-

19

18

 

9 1/8

-

19.10

59.4

S

60 1/4

 

 

20 1/4

9 1/4

-

19.22

59.7

-

-

 

 

 

9 3/8

-

19.31

60.0

S 1/2

-

 

 

 

9 1/2

.764

19.41

60.3

-

-

19 1/2

19

 

9 5/8

-

19.51

60.6

T

61 1/2

 

 

21 1/2

9 3/4

-

19.62

60.9

-

-

 

 

 

10

.781

19.84

61.6

T 1/2

-

20

20

 

10 1/4

-

20.02

62.2

U

62 3/4

 

21

22 3/4

10 1/2

.797

20.20

62.8

U 1/2

-

20 1/4

22

 

10 5/8

-

20.32

63.1

V

63

 

 

23 3/4

10 3/4

-

20.44

63.5

-

-

 

 

 

11

.814

20.68

64.1

V 1/2

-

20 3/4

23

 

11 1/8

-

20.76

64.3

W

65

 

 

25

11 1/4

-

20.85

64.7

-

-

 

 

 

11 3/8

-

20.94

65.0

W 1/2

-

 

 

 

11 1/2

-

21.08

65.3

-

-

21

24

 

11 5/8

.830

21.18

65.7

X

66 1/4

 

 

26 1/4

11 3/4

-

21.24

66.0

-

-

 

 

 

11 7/8

-

21.30

66.3

X 1/2

-

 

 

 

12

.846

21.49

66.6

Y

67 1/2

21 1/4

25

27 1/2

12 1/4

-

21.69

67.2

Y 1/2

-

 

 

 

12 1/2

.862

21.89

67.9

Z

68 3/4

21 3/4

26

28 3/4

12 3/4

-

22.10

68.5

Z 1/2

-

 

 

 

13

.879

22.33

69.1

-

-

22

27

 

 


WINDERS (clock keys)

Click here to buy Watch & Clock Keys (all keys)

Measure any edge of the winding square ('peg') in the clock in millimetres,
use the following conversion, top line is key number, bottom line is mm:

000

00

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

1.75

2.0

2.25

2.5

2.75

3.0

        3.25

3.5

3.75

4.0

4.25

4.5

4.75

5.0

5.25

5.50

5.75

6.00

 

WINDERS (watch keys)

Click here to buy Watch & Clock Keys (all keys)

 

EUROPEAN KEY NUMBER
SIZE IN MM
BRITISH KEY NUMBER
00
2.00
12
0
1.90
11
1
1.80
10
2
1.75
9
3
1.65
8
4
1.60
7
5
1.50
6
6
1.40
5
7
1.30
4
8
1.20
3
9
1.15
2
10
1.05
1
11
1.00
0
12
0.95
00
 




WEIGHTS Click here to buy weighing machines
Click here for our guide to buying weighing machines

 

Gold and silver is weighed in Troy ounces (ozt).  The Troy ounce, today, is only used for weighing precious metals (it was once used for weighing mail too). Do not confuse the Troy ounce (ozt)  with the Avoirdupois ounce (oz) which is used for weighing food and goods (e.g. kitchen scales and bathroom scales). Manufacturers of weighing machines outside the U.K. sometimes refer to the Avoirdupois ounce as the 'English Ounce'

...however... for lightweight items of gold and silver we use grams.  

The one figure you have to remember when weighing gold is: 31.1035g. = 1ozt.
or if you deal in heavy silver items, 32.1507 ozt = 1Kg.

1 TROY OUNCE =
0.911 Avoirdupois oz (ounce) - used for weighing food and goods
31.1035g. (grams) - THE standard unit of weight
20dwt (pennyweight) - the pre-decimal system in the U.K, still used in U.S.A.
480gr. (grains) - used for weighing powder when making up ammunition

TO CONVERT TO GRAMS

Avoirdupois oz = 28.35g.  (exact = 28.349523125g.)
Troy oz (ozt) = 31.103g. (exact = 31.1034768g.)
1lb (pound.) = 453.6g. (exact = 453.59237g.)
ct. (metric carat) = 0.2g.  - used for weighing diamonds
dwt (pennyweight) = 1.56g. (Exact = 1.55517384g.)
gr (grain) = 0.065g. (Exact = 0.06479891g.)
mom (momme) = 3.75g. - Japan, used for weighing pearls
tl (tael) = 37.8g. (Exact = 37.7994g.) - Hong Kong and Singapore

THE METRIC SYSTEM There are two different ounces but there is only one metric system.
For weighing diamonds:100pts (points) = 1ct, 5ct (carat) = 1g.
For all food and goods, and in science: 1000g. = 1Kg.

CONVERT ANY UNIT OF WEIGHT TO ANY OTHER UNIT OF WEIGHT

If you are converting weight to calculate the price of gold (priced in U.S. Dollars per Troy ounce of pure, 24ct, gold:

CURRENCY CONVERTER (this is the one eBay uses)

 

Please email me if any of these links are out of date
QUICKTEST, Watford, WD18 8PH, Tel. 01923 220206, email info(at)quicktest.co.uk